<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div></div>
  </body>
</html>
<script>
  // mvc
  // model 数据模型  v => view 视图 c => controller
  let str = "我的一个html";
  let dom = document.querySelector("div");
  dom.innerHTML = str;
  setTimeout(() => {
    str = "我是一个菜鸟";
    dom.innerHTML = str;
  }, 1000);
</script>
